Plastic cap making apparatus



April 24, 1951' l E, A. KEHoE ET Al.`

PLASTIC CAP MAKING APPARATUS Filed May 6, 1'948 5. Sheets-Shet l IN VEN TORS April 24, 1.1 951 E. A. KHOE ET Al. 2,550,567

` PLASTIC CAP MAKING APPARATUS `Film May 6, 1948 y s sheets-sheet 2 NVENToRs n i ["3 BY A155124, 195,1 EA. KEHQE4 ETAL 2,550,567 I PLASTIC CAP MAKING APPARATUS Filed May 6, 1948 s sheets-sheet 5 Patented Apr. 24, 419E-i1 OFFICE PLASTIC CAP' MAKING APPARATU Ellsworth A. Kehoe and Theodore R.. Burr, Rochester, N. Y., assignors to General Motors Corporation, Detroit, Mich., a corporation ofDela- Ware Application May 6, 1948, Serial No. 25,494

Claims.

heres to the thimble forms as they are withdrawn .from the. plastic. The forms being moved by the conveyor through surrounding air which cures the. .adhering plastic to form thimbles. Each barandthe thimble forms supportedv thereby providespassages. for receiving compressed air which is. .admitted to the bars successively in order to blow the thimbles from the forms.

` Further objects and advantages of the present invention will bev apparent from the following .descriptiom reference being had to the accompanying. drawings wherein a preferred embodiment of the present invention is clearly shown.

In the. drawings:

Fig. 1 is a plan view of. thethimble-forming inachine.;

Fig. 2Y isa fragmentary sectional view on line 2--2 of Fig. 5; v

Fig. 3 isa fragmentary viewin the direction of arrow 3 of Fig. 5;

4 isa front view in the direction of arrow 4AofFig. 1;

Fig. 5 is a side-view inthe direction of arrow 5 of` Fig. 4;.

Figs. 6 and '7 are sectional views taken respectively on lines 5 6 and i--l of Fig. 5, Fig. 7 being .drawn to a larger scale;

Fig. 8 is a view in the direction of arrow 3 of Fig.' '7.

Referring 4to Fig. 5, the conveyor comprises two chainszil which pass around pairs of sprock.- etsZ-I, 22, 23, 2t supported respectively by shafts 25, 26,. 2l, 28Aand which provide spaced trunnions29 (Fig. 6) which are received in sockets 3u (Figl) of bars 3l. Each bar 3l supports a plurality of thimble-forms 32, each having a central passage 33 connected with` a plurality of small outlet holes 34; and each central passage 33 is in communication with a passage 35 provided by the'bar 3l.. Referring to Fig. 6, shafts. 25 and 26 arejournaled in bearing bracketsl 3l and 38, re- `spectivelywhich are attached to the ends of rods 39 which are supported by vertical movement by sleeves 40 which are attached to a platelil which ari-angle 42 attaches to two plates 43. Plates 43 are supported by a .vertical frame 44 comprising vertical angle bars 45 vand horizontal angle bars 46. 1 The vertical frame 44 is connected by angle bars 41 andV 48 with another vertical frame. 54]

2V comprising vertical angle-bars 5I and an horizontal' bar 52. Frames. 44 and 59 are connected by angle bar ill (see also Fig. 4) with a third upright frame 51% comprising vertical angle bars 55 and horizontal. angle bars and 5l.

Shaft 2l is supported by bearing brackets 58 which are attached to two bars 59, the lower portions ofV which are attached to anglebar 5l and the Vupper portions of which are attached to an angle bar 59' attached to two bars l attached to the upper angle bar 45 of frame 44;

The sprocket shaft 28 (Fig. 2) is supported by brackets S2 attached' to two bars .53 attached to angle bar 5l of frame 5!! and to lower angle bar 46 of frame 45. Bars 5! support bars 65 which having plain holes receiving screws BE attached to bars 5l integral with a bar 658 (Figs. 5 and '7) providing a compressed air manifold including a passage. 59' connected with branch passages '.'0 .and with a hose il connected with a compressed airsource. Nuts l2 are adiustable on screws 6B for the purpose of locating the bar 68 so that it will be firmly engaged by the bars 3| as they are moved successively into engagement with bar 58 by the conveyor.

The conveyor chains 2t are moved in the direction. of arrows ll and i3 (Fig. 5) by an electricy motor 8l! mounted on a frame 8| and connectedby a coupling 8.2 with the input shaft 83 of a speed reducer in a case 84 and connected by a coupling 35 with a speed reducer in a case 86 and having its shaft 8l connected by a coupling 38 with shaft 2l. Frame 89' supports gear reducer housings 84 and 8S. The thirnbles are moved successively (five at a time) below the surface indicated by line et of heated air curing plastic which is kept in circulation by means, not shown, and overflows a weir 91| and thence into aheat insulated tank 92. As the thimble forms, coated with the'plastic, move in the direction of arrow l5; the plastic adhering to the form-s cures or setsv to form thimbles which are blown off when.- erer the form is subjected to compressed air which occurs when the bar 3l supporting them passes under the air manifold bar 5B.

To facilitate. access to the tank 92, it is desirabie to elevate the conveyor. This is accomplished bymoving vthe rods 39 upwardly thereby moving the sprockets 2l and 22 and portions of the chainsA 2B. As shown in Fig. 6, the weight of sprocket shaft 25 and parts supported thereby is counterbalanced by weights It!) connected by cables lill passing over rods H32 and attached to sleevesI H33v surrounding the shaft 25. When the sprockets. 2i and 22 are raised the chains 26) remain in mesh with all the sprockets and do not sag down to interferewith ready access to the region immediately above the tank 92. V'Iflziisres-ult is accomplished by the novel arrangement of the sprockets 2|, 22, 23 and 24 as shown in Fig. 5.

The plastic compound and the equipment for containing, circulating and heating it are not per se parts of the present invention. The plastic compound which may be used with the present invention may be any one of a number of available aircuring plastics for example, a solution of ethyl cellulose in a suitable plasticiser.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. Apparatus for making thimbles from liquid plastic material, a coating of which cures quickly in air, said apparatus comprising a conveyor,

means for moving the conveyor continuously, a

frame for supporting the conveyor above a vessel containing the material; hollow thimble forms having holes in their bottom surfaces and moved by the conveyor into and out of liquid plastic material to form a coating on the sides and bottoms of the forms, said coating setting during movement of the forms from the plastic containing vessel; a manifold including passages spaced from the vessel; and means for applying compressed air to the manifold whereby when the forms pass the manifold the air will blow the set plastic thimbles from the forms.

2. Apparatus for making thimbles from liquid plastic material, a coating of which cures quickly in air, said apparatus comprising a tank for receiving the material; a hollow form to which a coating of plastic is applied; means of conducting compressed air tothe interior of the form to eject the coating in the shape of a thimble from the form, said means comprising a movable form holder having a duct connected with the interior of the form; a fixed plate spaced from the tank with which the holder is brought into engagement after the form supported thereby has received a coating of material which has been cured in air, said plate having a duct connected with if;

a compressed air source and with which'the duct in the holder communicates during a portion of movement of the holder; and a continuously moving conveyor for carrying the holder into positions for causing the submersion of the form into and out of the material and for causing it to pass through air to effect curing of the coating received by the form and for causing the holder to engage the fixed plate.

3. Apparatus for making thimbles from liquid plastic material, a coating of which cures quickly in air, said apparatus comprising a tank for receiving the material; bars from each of which a plurality of thimble forms are suspended each bar having passages connected with the interior of the forms and extending to the upperside of the bars; a xed manifold spaced from the tank, said manifold having a duct connected with a compressed air source and providing openings communicating with the duct and aligned with bar passages when the bars engage the underside of the manifold; a continuously moving chain conveyor for moving the bars for causing the forms to dip into and out of the material to form a coating on the lower ends of the forms, and for causing the forms to pass through air to effect setting of the coating received by the forms and causing the holders to engage the manifold; rst, second, third, and fourth pairs of sprockets for supporting the conveyor chain above the tank,

4 said sprockets being so arranged that the axes of the sprockets are in parallel relation, the axes of rst and second pairs of sprockets being in vertical alignment directly above the tank and the axes of the third and fourth pairs of sprockets being at levels between the levels of the axes of the rst and second pair of sprockets, said axis of the third pair of sprockets being at a level nearer to the level of the second pair of sprockets than the axis of the four pair of sprockets, said axis of the third pair of sprockets being spaced a greater distance from the vertical plane of the axes of the rst and second pairs of sprockets than the axis of the fourth pair of sprockets;

and a vertical adjustable support for the first and second pairs of sprockets to raise said sprockets to provide access to the region above the tanks by elevating the first and second pairs of sprockets, said arrangement of sprockets being such that the chain will remain, during adjustment, in mesh with all the sprockets and any sag in the chains does not' interfere with the ready access to said region above the tank, the fourth pair of sprockets being directly below the fixed manifold to place the bars successively in contact with the manifold.

4. Apparatus for applying a coating of liquid to objects, said apparatus comprising a tank for receiving the coating liquid; supports for the objects to be coated; a chain conveyor for moving the supports to carry the objects into and out of the tank; rst, second, third and fourth sprockets for supporting the chain conveyor above a vessel containing the coating liquid, said sprockets being so arranged that the axes of the sprockets are in parallel relation, the axes of the rst and second sprockets being in vertical alignment and directly above the tank and the axes of the third and fourth sprocket being at levels between the levels of the axes of the rst and second sprockets, said axis of the third sprocket being at a level closer to the level of the second sprocket than the axis of the fourth sprocket, said axis of the third sprocket being further from the vertical plane of the axes of the first and second sprockets than the axis of the fourth sprocket; and a vertically adjustable support for the first and second sprockets to provide access to the region above the tank by elevating the first and second sprockets while the chain remains in engagement with all the sprockets.

5. Apparatus for making thimbles from liquid plastic material, a coating of which cures quickly in air, said apparatus comprising, a tank for receiving the material, plates from which a plurality of hollow thimble forms are suspended each plate having passages connected with the interior of the forms and extending to the upper side of the plate; a xed manifold spaced from the tank, said manifold having a duct connected with a compressed air source and providing openings communicating with duct and aligned with the plate passages when the plates engage the underside of the manifold for conducting compressed air to the interior of the forms to eject the coating in the form of thimbles; a continuously moving double endless conveyor for moving the plates for causing the forms to dip into and out of the material to form a coating on the lower ends of the forms and for causing the forms to pass through air to effect curing of the coating received by the for-ms and causing the plates to engage the manifold, Said plates being pivotally supported on the chains of the conveyors so that the center of the mass of each plate and its forms is below the pivotal points of the plate so that center of the mass and the pivotal points will be in vertical alignment causing the upper edges of all coatings on their respective forms to be symmetrical and for causing the upper side 5 of the plate to be on a horizontal plane as the plates engage the under side of the manifold.

ELLSWORTH A. KEHOE. THEoDoRE R. BURR.

8V Y REFERENGES CITED The following references are of record in the Y 111e of this patent:

UNITED STATES PATENTS 

1. APPARATUS FOR MAKING THIMBLES FROM LIQUID PLASTIC MATERIAL, A COATING OF WHICH CURES QUICKLY IN AIR, SAID APPARATUS COMPRISING A CONVEYOR, MEANS FOR MOVING THE CONVEYOR CONTINUOUSLY, A FRAME FOR SUPPORTING THE CONVEYOR ABOVE A VESSEL CONTAINING THE MATERIAL; HOLLOW THIMBLE FORMS HAVING HOLES IN THEIR BOTTOM SURFACES AND MOVED BY THE CONVEYOR INTO AND OUT OF LIQUID PLASTIC MATERIAL TO FORM A COATING ON THE SIDES AND 